Lear Natrosound NS-U1 – The Crossfeed IEM

As a competitive swimmer my first trip into audio was copying my hero Michael Phelps and getting a pair of Beats. With the help of Josh and a desire for more, I soon found that audio reproduction can be MUCH better. Look where we are now.

Lear have been one of the most innovative companies in the IEM scene in recent years. Starting with quite simple multi armature designs, they evolved into new technologies and with the likes of the BD4.2 (soon to be reviewed) started to really differentiate themselves from the others, not only with its internal design but also in new shell materials and tweaks for CIEM design. While they continue to makes strides with traditional IEMs and CIEMs, as of last year they started another project, something even more out there and exotic. It is all based around a new technology they are pioneering called Natrosound or NSS (Natural Stereo Sound)! The bottom line is quite simple, to achieve the sensation of true stereo sound (2 channel speakers) via an earphone. The technology it uses is similar to the idea behind digital crossfeed designs some companies have toyed with in the past but is no longer acting just on a digital plane. The way they plan to carry this out is via making earphones with dual drivers, but instead of splitting the frequency response between them, they are splitting the channels, one playing the correct channel as normal while the other one plays the opposite channel at a lower volume with the slightest of delay, as would be the case when listening to speakers, you never just hear a single channel like is the norm with earphones, it is also the reason why binaural files are so effective!

The NS journey started with demos of the technology in action, with Tatco Ma of Lear & Forever Source Digital in Hong Kong creating binaural YouTube videos you could watch with earphones to hear first a pair of speakers play a song, then a standard earphone and finally an NS earphone, with it being remarkable how close the NS model got to a traditional pair of loudspeakers. With a positive reaction to the videos they decided to make the first NS earphone, asking for crowdfunding to help make it possible and also make a studio for supporting local musicians in Hong Kong! The project was successful and the first NS earphone were created, the NS-U1! It is the NS-U1 I will be reviewing now but I technically have a new revised 2016 edition, which made some changes based on early feedback of the original. The NS technology has also been implemented in a LUF (Lear Universal Fit) and LCM (Lear Custom Monitor) series model for a bit more dollar, so you could go straight into the deep end with a custom version showcasing this technology. They will of course set you back more money than the NS-U1 though that costs 1688HKD (£150) or 2000HKD with custom ear tips (£175). That price also includes the NSC-03 cable which is 450HKD (£40) on its own. Right lets get to it!

Inside

Coming in the same iPhone style packaging as the AE1d and BD4.2 that arrived along side this from Lear, we have a simple but clean presentation inside showing off their PC-1 premium case which is already holding the earphones and then below is a little accessory box, just like with Unique Melody’s Maestro! The accessory haul is not much beyond the second cable offering a different feature set and some silicone and foam tips. I do want to mention the silky soft tub that is included as although it is not the most portable of cases, it feels amazing and has a great locking mechanism. It even has a softer silicone inside. I appreciate a case that is different from the usual.

Onto the earphones and they are some big old things, reminding me of the old Shure shells (E2c days) just bigger, and while I expect the size from the earphones with drivers in the double figures, I was hoping these would be a bit more slender even though they are packed with different but still vital tech. The ergonomics do worry me… especially with the way the cable connectors stick out like a sore thumb due to them being new propriety method with 4 points of contact, similar to what the Siren Series from JH has. It is so long it sticks out of my ear space when being worn and my ears are pretty largely sized. When I actually put them in my ear they immediately feel big but for a while feel light and comfy. Only after spending a bit more time do they feel just a bit out of place as if the curves in the shell and the angle of the nozzle is just not quite right. I also must stress that if you have smaller ears they could certainly be an issue. Josh was proof of this! I was surprised that they had pretty solid insertion depth for a fat earphone and isolation was as good as you can expect from a vented dynamic IEM.

There is something about the build quality I am just not quite getting behind. Maybe its because I find them plain ugly looking, even with the new blue/black colour scheme. The cheap plastic, while held together, has plenty of obvious seams that do not run smooth under your finger. Likely they will be fine on the long run but when you look at what RHA and Trinity are offering for cheaper with their metal housings, you can’t stop me from starting to expect that sort of quality. Even the DIY-esque LZ A3 from China has solid metal housing.

The cables also have some details I am not a fan of. While the bulky plastic controls on both iterations are necessary, the poor memory wire (it doesn’t actually fit over your ear) is not, and neither is the right angled jack that is exceptionally long, completely defeating the purpose of a 90 degree angle for a plug, to keep a low profile.

Not Just a Material Difference

The special NS tech featured in these earphones is controlled solely by the cable you have in use, be it the standard NSC-01 cable or the more flexible NSC-03, originally an optional add on, now a standard accessory.

Regardless of the cable, having NS on is simply a choice. You can listen to it off and then turn it on when you so desire, with immediate effect and easy access. When off these are no different to simply listing to a 6mm CCAW neodymium magnet, dynamic driven earphone and that could be your thing but if you want to actually take advantage of the acoustic crossfeed and involve the second 6mm driver you will want to turn NS on.

The simpler NSC-01 cable has two small plastic boxes on the cable, the first being a play/pause button (can answer calls and talk via mic if using with phone) and sits high up the right cable. The second doubles up as an NS on/off switch and does just that, lets you have natrosound engaged or have a more basic listening experience.

The NSC-03 takes away the single button remote/mic function but adds much more versatility in regard to sound scoping. While the bigger y-split on the 03 also has the NS on/off switch on the front, it then has two dials on the side. One is a bass boost, which is available to your needs regardless of whether your are listening to just one or both of the drivers. Then you have NS switch that after switching natrosound on allows you to change how much you want it to be in action.

Other than the different uses, the cables are the same, in material and connection points. The NSC-03 having a cable cinch is the only exception to that rule.